Differential serum interferon-β levels in autoimmune thyroid diseases

Introduction: Interferon (IFN)-β is known as an environmental trigger for the occurrence of autoimmune thyroid disease (AITD). However, the association of another type-1 IFN, IFN-β, with AITD is unknown. Material and methods: In the study, we explored the association of serum IFN-β levels with AITD in an ethnic Chinese (i.e., Taiwanese) population. We enrolled 160 patients with Graves’ disease (GD), 47 patients with Hashimoto’s thyroiditis (HT), and 119 healthy controls. Serum IFN-β and B-cell activating factor (BAFF) levels were quantified in healthy controls at the baseline and in patients with AITD either prior to receiving medication or while under medication. Thyroid function and thyroid-stimulating hormone receptor antibody (TSHRAb) levels were measured at the time of serum collection. Results: Serum IFN-β levels were lower in the HT group than in the control group (p = 0.031). A significant inverse correlation was observed between IFN-β and TSHRAb levels in men with GD (r = –0.433, p = 0.044). Serum IFN-β levels were also negatively associated with BAFF levels in men with GD, HT, and AITD (r = –0.320, p = 0.032; r = –0.817, p = 0.047; and r = –0.354, p = 0.011, respectively), but not in women with GD, HT, or AITD. Conclusions: Serum IFN-β levels were lower in HT patients. Correlations of serum IFN-β with TSHRAb and BAFF levels were found to be gender-specific. Further well-designed studies with larger sample sizes are required to confirm our findings.